How to lower noise floor through mods?


I have an older tube preamp which I like very much. It has something of a lush "romantic" aspect which I quite enjoy, and while it is not 'noisy', it is not the quietest pre out there. In addition, I think that one might be able to maintain the 'romance' but improve the transients a bit. I have done a fair bit of research on replacing the caps (which I should do anyway because of age probably), but I am wondering what mods would lower the noise floor.

Will new/better caps help? Resistors too? Tubes? Is it new wiring for the point-to-point parts?

Modders & Manufacturers, please toss your 2cts in! I would love to hear your experiences and wisdom. What will keep the 'romance' and euphony while lowering the noise floor and improving transients?
t_bone
Before you sign on for expensive mods, why not start with some Vibrapod cones and isolators. I use Vibrapods under much of my gear, and I just put a special arrangement of Vibrapods under my turntable which has catapulted its performance to the next level.

For as little as $56 and no shop time, you could find out how far the Vibrapods take you where you want to go. See here and here.

Disclaimer: I have no financial interest in Vibrapod; I've been an enthusiastic customer for over a dozen years, and they sometimes still surprise me.
Tubes that are tested for low noise might be the place to start. This would be a "plug and play" mod requiring only the effort to locate and purchase the tubes. But that romance and euphony might just be a product of noisy/micro phonic tubes. You won't know until you try.
Both caps and resistors will likely increase resolution and lower perceived noise floor. Retaining the tonal balance with these upgrades is a delicate balancing act. Most caps I've dealt with increase brightness to some degree, usually this can be adjusted for elsewhere in the system.

Modding power supplies may be helpful as well, particularly with the transients. I'm upgrading my Cayin's phono pre bridge rectifiers with HEXFRED's and bypassing the electrolytic caps with film caps next week, should have some answers soon. I'm looking for increased transient behavior, specifically more slam.

If you do go the modding route, just remember you can always undo the changes. I've also found modding to be the most interesting aspect of this hobby, really amazing sonic upgrades here! Endlessly replacing components is way too costly and relatively boring.

Mods are the way to go if you have some guts and soldering skills! Practice on cheaper pieces, gradually working your way up to more expensive components.
T bone, just looked at your system, like it! Also looks like you're comfortable with a fair amount of DIY.

The Jadis pre is nice, some VH Audio V-Caps, or better yet, some Duelund copper foil caps (depending on voltage ratings) should both give you what you're looking for. Others may have other cap suggestions, but the two caps mentioned above have to be on anyone's list of primo caps.

The Texas Components Vishay nude resistors (TX2575) are reportedly the best (I'll be making this upgrade soon to the Cayin). The Jadis is mostly point to point wiring which should makes cap and resistor upgrades easier.

Internal wiring would be my last upgrade, I like Mundorf Silver/Gold. Many others to choose from. NOS tubes and different isolation schemes may also prove very worthwhile.
Replace the rectifier(s)(whether a bridge or individual diodes) with soft recovery IXYS FREDs or CREE SiC Schottkys:(http://www.partsconnexion.com/catalog/semiconductors.html), and rewire internals with a good cable, like Kimber KCAG, going to a star ground with what would be the negative conductor and placing small ferrite beads on the positive conductors, at the source ends. Be certain your wiring is run tightly against the chassis, and(as much as possible) tucked in the bends along the outside of the chassis.